Description: (Applicant's Description) This Cell Culture and Expression Shared Resource serves as a centralized resource for cell and tissue culture media and a cell line repository, including retroviral packaging cell lines. The goals of this resource are: (1) to provide Cancer Center members with a convenient, reliable, and inexpensive source of standard culture media for mammalian cell culture, as well as antibiotics, and serum, (2) to serve as a repository for cell-lines routinely used in cancer research, (3) to perform tests of tissue culture media and sera for Mycoplasma contamination, and (4) provide retroviral expression services through transfection of viral packaging cell-lines.